WJA provides clarity on burst disc colour coding

The Water Jetting Association has moved to end uncertainty about the use of plastic-style burst discs in jetting systems by publishing the colour codes for the pressure safety devices as specified by the manufacturers in its codes of practice.

The burst discs, also referred to as bursting discs or rupture discs, are single-use, non-reclosing safety devices designed to protect pressurised systems from overpressure.

Vital to use right burst discs

They are colour coded, according to a range of set pressure levels, but the WJA was concerned that some equipment users could be unsure of the pressures that each colour represent.

Metal burst discs, which are not colour-coded, are used in some high pressure and ultra-high pressure water jetting systems.

WJA Technical Manager Gordon Taylor said: “To clarify the situation, the colours for burst discs at each pressure level are now stated in our three codes of practice – the blue, red, and purple codes.

“This is an important safety issue. If the wrong burst disc is used in water jetting equipment, the safety system designed to protect operatives from harm could be compromised or fail entirely.

“Equipment users must always refer to the manufacturer’s or equipment supplier’s operating instructions to ensure the correct burst disc is fitted to the equipment they are using.”

Controlled reduction of pressure

Burst discs are precision-manufactured to weaken at a specific pressure, allowing the controlled reduction of pressure so equipment cannot fail catastrophically, risking injury to an operative or damage to equipment.

The WJA’s Blue Code is for the safe use of high and ultra-high-pressure water jetting equipment. The Red Code is for the safe use of water jetting equipment in drains and sewers. The Purple Code is for the safe use of pressure washers.

Download the WJA Guide to Burst Disc Colour Codes.